Fix duplicated recommended project since github url's are case insensitive

Currently there are several repeated entries due to the fact that Github projects urls are case Insensitive, for instance: 

![screen shot 2013-12-05 at 8 29 30 am](https://f.cloud.github.com/assets/845590/1682768/e3ff727e-5db1-11e3-82ef-8fac63df31a1.png)

This fix prevents more duplication, but a manual cleanup will be necessary to clear the records that are already duplicated.